1. Field of the Invention
The present invention relates to a valve apparatus of an enclosed reciprocating compressor, and more particularly to the valve apparatus therefor which opens and closes a discharge hole for compressed gas.
2. Description of the Prior Art
A conventional enclosed reciprocating compressor includes, as illustrated in FIG. 1, driving means 20 having a rotor 21 and a stator 22 disposed at an upper side in an upper and a lower case 10 and 11, a crank axis 40 having an eccentric unit 41 disposed at an inner lower side of the rotor 21 through the medium of a bearing 30 and an oil pickup tube 50 disposed at a lower end of the eccentric unit 41 for being eccentrically moved by turning effect of a crank shaft 40 and for picking up oil (o) stored at a lower side in a lower case 11 to thereby supply the oil to the eccentric unit 41 and a spiral groove 42 formed at the crank shaft 40.
The eccentric unit 41 of the crank shaft 40 is disposed with a connecting rod 60 for receiving an eccentric movement according to the turning effect of the crank shaft 40 to thereby convert the movement to horizontal reciprocating movement.
The connecting rod 60 is disposed at a tip end thereof with a piston 80 for moving horizontally and reciprocally in a cylinder block 70 mounted at one side in the lower case 11.
The cylinder block 70 is arranged at one side thereof with a cylinder head 90 having suction and discharge chambers 91 and 92 for high pressurized gas to be sucked in and discharged there through.
Furthermore, the suction chamber 91 is provided at one side thereof with a silencer 100 for attenuating moise generated in the course of mixed gas being sucked in, and is arranged at the other side thereof with a capillary tube 110 for supplying the oil (o) stored at a lower side in the lower case 11 to the suction chamber 91 when a piston 80 is horizontally and reciprocating moved in the cylinder block 70.
Meanwhile, a valve plate 120 having a suction inlet 121 is disposed between the cylinder block 70 and the cylinder head 90.
A suction valve 130 is disposed between the cylinder block 70 and the valve plate 120 for being opened and closed by pressure generated by the high pressurized gas sucked from the suction chamber 91 to the cylinder block 70 when the piston 80 is moved to a bottom dead center.
Gaskets 140 are respectively provided between the cylinder head 90 and the valve plate 120 and between the cylinder block 70 and suction valve 130.
At this time, the valve plate 120 is concavely formed at an upper center area thereof with a first accommodation unit 122 for accommodating a keeper member 170 to accurately place a discharge valve 150 and a stopper valve 160 at a predetermined position.
The first accommodation unit 122 is centrally formed with the charge valve 150 for being opened and closed by pressure generated by the high-pressurized gas discharged from the cylinder block 70 to the chitchatted chamber 92 when the piston 80 is moved to an upper dead point, and is also concavely formed with a second accommodation unit 123 for accommodating the stopper valve 160 so that the discharge valve 150 thereof can be restricted in area of closing and opening.
The second accommodation unit 123 is centrally arranged with a discharge hole 124 for discharging the high pressurized gas from the cylinder block 70 to the discharge chamber 92.
In other words, the second accommodation unit 123 is formed at one end thereof with a support groove 123a for accommodating respective valve fixing units 151 and 161 formed at tip ends of the discharge valve 150 and the stopper valve 160 to thereby allow valve movement units 152 and 162 disposed at the other tip ends to vertically move to the left and right directions without being swayed.
The second accommodation unit 123 is also formed at the other end thereof with a support space 123b having a discharge hole 124 at a central portion thereof in order to allow the high-pressurized gas to be discharged from the cylinder block 70 to the discharge chamber 92 and to allow the valve movement unit 152 at the discharge valve 150 to be opened and closed while being smoothly and vertically moved.
At this time, the stopper valve 160 is formed with a bend unit 163 between the valve fixing unit 161 and the valve movement unit bent at a predetermined angle so as to limit an opened degree of the discharge valve 150 and to alleviate trembling of the discharge valve 150.
The bend unit 163 serves to press straightly on an upper surface of the discharge valve 150 by way of a line contact.
Meanwhile, the keeper member 170 is respectively formed at both ends thereof with bend units 171 symmetrically disposed at predetermined angles, being bent more than a central potion thereof, for being mounted at both ends of the first accommodation unit of the valve plate 120 to thereby press the valve fixing units 151 and 161 of the stopper valve 160 and the discharge valve 150.
When the piston 80 in the cylinder block 70 thus constructed is moved to an upper dead center, gas in the cylinder block 70 is compressed and at the same time, the valve movement unit 132 at the suction valve 130 returns to an original position according to pressure of high-pressurized gas compress thereby to thereby same to contact the suction hole 121 at the valve plate 120 and to close the hole 121.
Furthermore, the valve movement unit 152 of the discharge valve 150 which has blocked the discharge hole 124 is laid aside by pressure of the compressed high-pressured gas to thereby hit the valve movement unit 162 of the stopper valve 160, and the stopper valve 160 is retracted by the impact thereof until same reaches the keeper member 170, whereby the high-pressurized gas in the cylinder block 70 is discharged to the discharge chamber 92 of the cylinder head 90 through the discharge hole 124 of the valve plate 120.
When the discharge of high-pressurized gas is finished and the piston 80 is moved to a bottom dead center the valve movement unit 152 of the discharge valve 150 is returned to the original position by the resilient force of the stopper valve 160 and the restoring force of the discharge valve 150, thereby contacting the discharge hole 124 of the valve plate 120 and closing the hole 124.
When suction valve 130 is opened by vacuum pressure generated in the course of the piston 80 being moved to the bottom dead center, the gas in the suction chamber 91 at the cylinder head 90 is sucked into the cylinder head 70 through the suction hole 121, and therefore compression and discharge strokes are repeated.
However, there is a problem in the valve apparatus of an enclosed reciprocating compressor thus constructed in that, because a tip end of the valve movement unit 162 formed at the stopper valve 160 is always in touch with a bent shape of the bend unit 171 formed at the keeper member 170 during the suction stroke and discharge stroke of the high-pressurized gas, as illustrated in FIG. 3, the valve movement 162 of the stopper valve 160 performs an irregular movement according to pressure change during the discharge stroke and at the same time, abrades the keeper member 170 to thereby generate noises.
Furthermore, there is another problem in that, because the keeper member 170 is structured such that both ends thereof are mounted to the first accommodation unit 122 of the valve plate 120 and then assembled into a space between the valve plate 120 and the cylinder head 90 when they are assembled, the keeper member 170 is easily displaced by pressure change during the discharge stroke, to thereby prevent the discharge valve 150 and the stopper valve 160 from being steadily pressed so that there is generated a heavy vibration (trembling) of the discharge valve 150 and the stopper valve 160, and there possibly occurs detachment of the discharge valve 150 and the stopper valve 160.